Wow. This is a cautionary tale. I don't think I'd be as devastated as this poor chap, but as it grew I realize I've allowed my iCloud photo library to become a single copy. How are people handling this these days? If i wanted to ensure a full backup of everything on my iCloud to a NAS, what's the best way these days? Seems like they make it difficult by design..
I run Arq Backup automatically in the background. It copy Photos, iCloud files and my mails once every days to S3 with incremental backups. It requires to have a full copy locally. Works great! It is not hard to configure once, with the proper folders and settings.
yeah that's the thing. When my iPhotos library exceeded 1TB I lost the ability to store the full local copies. Since then, iCloud itself has been the sole source.
Looks like there's some decent, reasonably priced apps to handle this like https://apps.apple.com/us/app/parachute-backup/id6748614170?... (no affiliation)